Quick answer: GPT-5.3 Codex is OpenAI's January 2026 coding-specialised model scoring 20.3% LHTB. Proprietary — Codex-specialised variant in the GPT-5.3 line.
GPT-5.3 Codex is OpenAI's January 2026 coding-specialised release, designed for software development tasks. The LHTB score of 20.3% reflects the benchmark's general-task scope vs. the model's coding specialisation.
| Field | Value |
|---|---|
| Organization | OpenAI |
| License | Proprietary (API only) |
| Release date | January 2026 |
| Modality | Text only |
| Benchmark | Score | Source | Date |
|---|---|---|---|
| LHTB | 20.3% | Benchgen evaluation | 2026-01 |
Available via API. Refer to provider pricing.
| Model | LHTB | License |
|---|---|---|
| GPT 5 3 Codex | 20.3% | Proprietary |
| GPT-5.1 Codex | — | — |
Check the LHTB leaderboard for current comparisons.
Scores from Benchgen evaluations. Last updated 2026-07-24.